1. Field of the Invention
This invention relates to a connector that locks a terminal doubly by employing a locking lance of a connector housing and a spacer inserted into the connector housing and, more specifically, to the connector for locking a terminal doubly, wherein the lance and the spacer lock the same spot of the terminal.
2. Description of the Related Art
FIGS. 11 to 13 show a conventional double locking connector described in Japanese Utility Model Application Laid-Open No. H6-58570.
As shown in FIG. 11, the double locking connector 60 comprises: a male connector housing 61 made of synthetic resin; female terminals 64 each inserted from rear openings 62a of the connector housing 61 into terminal receiving chambers 62 (see FIG. 12); and a spacer 67 made of synthetic resin for locking the terminals 64 each inserted from opening 66 of walls 65 at the bottom of the connector housing 61 into the connector housing 61 at a right angle to a direction of inserting the terminal.
In the connector housing 61, there is formed a space 68 into which the spacer 67 is inserted. As for this conventional example of the double locking connector 60, two rows of the chambers 62 for receiving the terminals 64 are disposed vertically in the connecter housing 61 and each chamber 62 extends from the front of the connector housing 61 to the rear thereof with a space 68 for receiving the spacer 67 at a mid portion along the length thereof. A flexible lance (arm) 70 for primarily locking a terminal 64 is formed on an upper wall 69 of the chamber 62 and a projection 71 at the end of the lance 70 faces the chamber 62.
The terminal 64 is manufactured by punching out from a conductive metal plate followed by bending processing and has an electric contact 86 at the first half thereof and a pressure welding part 72 at the latter half thereof. A rectangular engaging hole 73 for receiving the projection 71 of the lance 70 is formed on an upper wall of the electric contact 86 and a pair of stabilizers 74 arises from both sides of the engaging hole 73. A spring (not shown in the figure) for contacting is inserted inside the electric contact 86. The pressure welding part 72 consists of a contact piece 72a to be pressure welded to conductors of the wire at the front portion thereof (see FIG. 12) and a clamping piece 72b to clamp an insulator of the wire at the rear portion thereof.
The spacer 67 comprises: a substrate 75 for closing the opening 66; a plurality of partitions 76 vertically arose from the substrate 75; a wall 77 for connecting upper ends of the partitions 76; a protrusion 78 for secondarily locking the terminals 64 formed in parallel on the wall 77; and a pair of locking walls 79 arose vertically from the substrate 75. Each part 80 of the respective chamber 62 is formed between the corresponding partitions 76. Each protrusion 78 has an inclined plane 78a on which an end of the terminal 64 slidably abuts. The locking wall 79 has a flexible claw 82 engaging with an engaging portion 81 of the connector housing 61.
As shown in FIG. 12, the terminal 64 is inserted into the terminal receiving chamber 62 under such condition that the spacer 67 is temporarily locked to the connector housing 61. The terminal 64 pushes down the protrusion 78 of the spacer 67 to bring the spacer 67 in a temporary locking state and is advanced by pushing up the lance 70.
As shown in FIG. 13, when the terminal 64 is completely inserted into the connecter housing 61, the lance 70 resiliently restores its original state and the projection 71 engages with the engaging hole 73 of the terminal 64, thereby the terminal 64 is primarily locked. Then, the spacer 67 is inserted in a direction shown by an arrow D of FIG. 13 and a front end of the projection 78 abuts on a shoulder (a rear end) 83 of the electric contact 86 of the terminal 64, thereby the terminal 64 is secondarily locked. That is, the terminal 64 is doubly locked by the lance 70 and the spacer 67, thereby the terminal 64 is securely prevented from coming off.
If the terminal 64 is incompletely inserted into the connecter housing 61, the protrusion 78 hits a bottom surface 84 (see FIG. 13) of, the electric contact 86 of the terminal 64 when the spacer 67 is inserted into the chamber 62, then the spacer 67 cannot be advanced any more, thereby the incomplete insertion of the terminal 64 can be detected by an operator.
However, as for the structure of the conventional double locking connector described above, if the position of the engaging hole 73 is shifted excessively to the front of the terminal 64 due to unevenness of the dimensions of the terminal 64 (based on the unevenness in manufacture thereof), the front end of the protrusion 78 of the spacer 67 abuts on the bottom surface 84 of the electric contact 86 of the terminal 64 even when the terminal 64 is completely inserted into the connecter housing 61, then the spacer 67 cannot be completely inserted, resulting in that the operator might mistakenly detect the state as an incomplete insertion of the terminal 64.
On the other hand, if the position of the engaging hole 73 is shifted excessively to the rear of the terminal 64, after the complete insertion of the terminal 64, the protrusion 78 of the spacer 67 engages with a shoulder (a rear end) 83 of the electric contact 86 of the terminal 64 to secondarily lock the terminal 64, however, the projection 71 of the lance 70 does not engage with the engaging hole 73 of the terminal 64, causing a problem that the terminal 64 cannot be locked primarily. In this case, the operator does not find a failure in the engagement of the lance 70, then the working process might be advanced to a next step leaving the terminal 64 to stay in such condition that the locking force of the terminal is weak.
Furthermore, if a length of the electric contact 86 is too long, even when the projection 71 of the lance 70 engages with the engaging hole 73 of the terminal 64 upon the complete insertion of the terminal 64, the protrusion 78 of the spacer 67 hits the electric contact 86 of the terminal 64. In this case, since the terminal is primarily locked by the lance 70, the terminal 64 cannot be come out even when the spacer 67 is come out and a wire 85 (see FIG. 13) connected to the terminal 64 is pulled. Then, such a time-consuming work is necessary that the engagement of the lance 70 is released by using a jig (not shown in the figure) and that the terminal 64 is replaced by another terminal.